1、班級(jí)姓名學(xué)號(hào)作業(yè)要求編寫程序計(jì)算圖1所示算例系統(tǒng)的潮流及三相短路電流。潮流計(jì)算：方法不限，計(jì)算系統(tǒng)的節(jié)點(diǎn)電壓和相角。短路電流：4號(hào)母線發(fā)生金屬性三相短路時(shí)（zf=0）,分別按照精確算法和近似算法計(jì)算短路電流、系統(tǒng)中各節(jié)點(diǎn)電壓以及網(wǎng)絡(luò)中各支路的電流分布，并對(duì)兩種情況下的計(jì)算結(jié)果進(jìn)行比較。圖13機(jī)9節(jié)點(diǎn)系統(tǒng)表19節(jié)點(diǎn)系統(tǒng)支路參數(shù)支路R(.)X(.)B/2(Tk)(.)140270390454657697889表29節(jié)點(diǎn)系統(tǒng)發(fā)電機(jī)參數(shù)發(fā)電機(jī)編號(hào)節(jié)點(diǎn)類型Pg(.)Vg(.)xd(.)E(.)1平衡2PV3PV表39節(jié)點(diǎn)系統(tǒng)負(fù)荷參數(shù)節(jié)點(diǎn)編號(hào)節(jié)點(diǎn)類型Pi(.)Qi(.)4PQ005PQ6PQ7PQ008P

2、Q19PQ00計(jì)算步驟進(jìn)行系統(tǒng)正常運(yùn)行狀態(tài)的潮流計(jì)算，求得U(0)形成不含發(fā)電機(jī)和負(fù)荷的節(jié)點(diǎn)導(dǎo)納矩陣Yn；將發(fā)電機(jī)表示為電流源&(杳/jXdi)和導(dǎo)納yi(1/jXdi)的并聯(lián)組合；節(jié)點(diǎn)負(fù)荷用恒阻抗的接地支路表示；形成包括所有發(fā)電機(jī)支路和負(fù)荷支路的節(jié)點(diǎn)導(dǎo)納矩陣丫，即在Yn中的發(fā)電機(jī)節(jié)點(diǎn)和負(fù)荷節(jié)點(diǎn)的自導(dǎo)納上分別增加發(fā)電機(jī)導(dǎo)納yi和負(fù)荷導(dǎo)納yLD,*(yLD,i利用Z利用公式利用公式利用公式SLD,iPLDijQLDi、22)，Vi2Vi2y1,計(jì)算節(jié)點(diǎn)阻抗矩陣，從而得到阻抗矩陣中的第f歹U；(6-7)或(6-10)計(jì)算短路電流；(6-8)或(6-11)計(jì)算系統(tǒng)中各節(jié)點(diǎn)電壓；(6-9)計(jì)算

3、變壓器支路的電流；對(duì)輸電線路利用n型等值電路計(jì)算支路電流。計(jì)算結(jié)果節(jié)點(diǎn)導(dǎo)納矩陣Yn：Columns1through500000000000+00+000+000+000+00+00000000+00Columns6through9000000+000000+0000+0000+0+00+0+電壓幅值:電壓相角:0節(jié)點(diǎn)有功：節(jié)點(diǎn)無(wú)功：修正后的節(jié)點(diǎn)導(dǎo)納矩陣Y：Columns1through50000+000000000000+00+000+000+000+00+00000000 +00Columns6through9000000+000000+0000+0000+0+00+0+節(jié)點(diǎn)阻抗矩陣Z的第4

4、列：+精確計(jì)算結(jié)果：短路電流：模值：相角：節(jié)點(diǎn)電壓模值：支路電流：ijIij14795+4 6+5 7+6 9+7 8+89+近似計(jì)算結(jié)果:短路電流：模值：相角:節(jié)點(diǎn)電壓模值:五、程序流程圖設(shè)置k-0及最大迭代次數(shù)Kmax六、程序及輸入文件文件:Sheetl9節(jié)點(diǎn)系統(tǒng)支路參數(shù)首節(jié)點(diǎn)編號(hào)i|尾節(jié)點(diǎn)編號(hào)jR(.)X(.)B/2(.)140027003900454657697889Sheet29節(jié)點(diǎn)系統(tǒng)發(fā)電機(jī)及負(fù)荷參數(shù)節(jié)點(diǎn)編號(hào)節(jié)點(diǎn)類型P(.)Q(.)U(.)Xd(.)E(.)1平衡2PV3PV4PQ005PQ6PQ7PQ008PQ-19PQ00文件：l=9;%支路數(shù)n=9;%節(jié)點(diǎn)數(shù)m=6;%PQ節(jié)點(diǎn)

5、數(shù)Yn=zeros(n);%初始化節(jié)點(diǎn)導(dǎo)納矩陣YDATA1=xlsread(",1);%計(jì)算節(jié)點(diǎn)導(dǎo)納矩陣Yfork=1:li=DATA1(k,1);j=DATA1(k,2);R=DATA1(k,3);X=DATA1(k,4);B2=DATA1(k,5);Yn(i,i尸Yn(i,i)+1i*B2+1/(R+1i*X);Yn(j,j尸Yn(j,j)+1i*B2+1/(R+1i*X);Yn(i,j)=Yn(i,j)-1/(R+1i*X);Yn(j,i)=Yn(j,i)-1/(R+1i*X);enddisp('節(jié)點(diǎn)導(dǎo)納矩陣Yn：');disp(Yn);G=real(Yn);B

6、=imag(Yn);DATA2=xlsread('',2);P=zeros(1,n);Q=zeros(1,n);U=ones(1,n);P(2:n)=DATA2(2:n,3);Q(4:n)=DATA2(4:n,4);U(1:3)=DATA2(1:3,5);%設(shè)置節(jié)點(diǎn)電壓初值e(1)=DATA2(1,5);e(2:n)=;f(1:n)=;%設(shè)置迭代次數(shù)t=0;tmax=10;whilet<=tmax%計(jì)算f(x)a(1:n)=;c(1:n)=;fori=2:nforj=1:na(i)=a(i)+G(i,j)*e(j)-B(i,j)*f(j);c(i)=c(i)+G(i,j)

7、*f(j)+B(i,j)*e(j);endendfori=2:ndeltaP(i)=P(i)-e(i)*a(i)-f(i)*c(i);endforj=4:ndeltaQ(j)=Q(j)-f(j)*a(j)+e(j)*c(j);endfork=2:3deltaU2(k)=U(k)*U(k)-e(k)*e(k)-f(k)*f(k);endfx=deltaP(2:n)deltaQ(4:n)deltaU2(2:3)'%計(jì)算雅克比矩陣Jfori=2:nforj=2:nifi=jH(i,j)=-(G(i,j)*e(i)+B(i,j)*f(i);N(i,j)=B(i,j)*e(i)-G(i,j)*f

8、(i);elseH(i,j)=-a(i)-(G(i,i)*e(i)+B(i,i)*f(i);N(i,j)=-c(i)+(B(i,i)*e(i)-G(i,i)*f(i);endendendfori=4:nforj=2:nifi=jM(i,j)=B(i,j)*e(i)-G(i,j)*f(i);L(i,j)=G(i,j)*e(i)+B(i,j)*f(i);elseM(i,j)=c(i)+(B(i,i)*e(i)-G(i,i)*f(i);L(i,j)=-a(i)+(G(i,i)*e(i)+B(i,i)*f(i);endendendfori=2:3forj=2:nifi=jR(i,j)=0;S(i,j)

9、=0;elseR(i,j)=-2*e(i);S(i,j)=-2*f(i);endendendJ=H(2:n,2:n)N(2:n,2:n);M(4:n,2:n)L(4:n,2:n);R(2:3,2:n)S(2:3,2:n);ifmax(abs(fx)<%輸出結(jié)果break;else%求解修正方程獲得dxdx=-JA(-1)*fx;dx=dx'e(2:n)=e(2:n)+dx(1:n-1);f(2:n)=f(2:n)+dx(n:2*(n-1);t=t+1;endendift>tmaxstr=潮流計(jì)算不收斂；disp(str);elsea(1:n)=;c(1:n)=;fori=1

10、:nforj=1:na(i)=a(i)+G(i,j)*e(j)-B(i,j)*f(j);c(i)=c(i)+G(i,j)*f(j)+B(i,j)*e(j);endendfori=1:nU(i)=e(i)+1i*f(i);amp(i)=abs(U(i);arg(i)=angle(U(i);P(i)=e(i)*a(i)+f(i)*c(i);Q(i)=f(i)*a(i)-e(i)*c(i);enddisp('電壓幅值：');disp(amp);disp('電壓相角：');disp(arg);disp('節(jié)點(diǎn)有功：)；disp(P);disp('節(jié)點(diǎn)無(wú)功

11、：');disp(Q);end%計(jì)算短路電流f=4;zf=;%修正節(jié)點(diǎn)導(dǎo)納矩陣Xd=DATA2(1:3,6);E=DATA2(1:3,7);fori=1:3Ii(i)=E(i)/(1i*Xd(i);endY=Yn;fori=1:3Y(i,i)=Y(i,i)+1/(1i*Xd(i);endforj=4:nY(j,j)=Y(j,j)+(-P(j)+1i*Q(j)/(U(j)*U(j);enddisp('修正后的節(jié)點(diǎn)導(dǎo)納矩陣Y:');disp(Y);Z=YA(-1);disp('節(jié)點(diǎn)阻抗矩陣Z的第4歹U:');disp(Z(:,4);%精確計(jì)算disp(

12、9;精確計(jì)算結(jié)果：');U0=U;If=U0(f)/(Z(f,f)+zf);amp=abs(If);arg=atand(imag(If)/real(If);disp('短路電流：)；disp('模值：');disp(amp);disp('相角：');disp(arg);fori=1:nU(i)=U0(i)-Z(i,f)*If;amp=abs(U);enddisp('節(jié)點(diǎn)電壓模值：)；disp(amp);disp('支路電流：');str='i''j''Iij'disp(str);fork=1:li=DATA1(k,1);j=DATA1(k,2);r=DATA1(k,3);x=DATA1(k,4);z=r+1i*x;I=(U(i)-U(j)/z;num2str(I);str=num2str(i)''num2str(j)disp(str);end%近似計(jì)算disp('近似計(jì)算結(jié)果：);U0(1:n)=;If=U0(f)/(Z(f,f)